Combination resetting guard for combination padlocks



Feb. 5, 1957 MILLER 2,780,087

COMBINATION RESETTING GUARD FOR COMBINATION PADLOCKS Filed April 16, 1954 m up.

IN VENTOR ly 6 Jill/e1 BYWM hrtmfl,

ATTORNEYS COMBINATEGN REEeETTlNG GUARD FOR QUMBENATION PADLOCKS The present invention relates in general to combination resetting means for combination locks, and more particularly to a combination lock of the exposed shackle padlock type having a facility for preventing access to the tumblers for resetting the combination or observance of the movement of the tumblers to achieve unauthorized unlocking of the lock at all times except when the lock has been unlocked and specially adjusted by persons having knowledge of the combination.

In combination locks of the general type herein involved having a plurality of rotary tumblers driven from an exposed dial, the combination can be reset at any time by inserting a combination changing key from externally of the locking housing through an opening usually provided in the rear cover plate of the housing and into openings in the tumblers which are aligned with the key opening in the rear cover plate when the tumblers are in a predetermined position. The insertion of the combination changing key into the openings provided therefor in the tumblers effects a release of the outer annular disk portion of the tumblers of conventional construction from their inner hub portion by which the tumblers are driven, so that the position of the inner hub portions of the tumblers relative to their outer annular disk portions may be reset to any desired combination by turning the dial and driving cam. Since padlocks of the type having exposed shackles are designed to he usually coupled through a hasp staple, the lock housing is exposed and freely available to inspection by persons seeking unauthorized admission to the enclosure protected by the padlock. In view of this condition, movement of the tumblers, or at least the the rearmost tumbler in these conventional combination locks may be observed through the combination changing key opening in the rear cover plate of the lock housing and persons having knowledge of the general structural features of this type of lock can fairly readily detect the combination of the lock by insertion of small pieces of material such as shim stock through the exposed combination changing key opening and thereby gain unauthorized admission to the locked enclosure.

It has heretofore been proposed as an expedient to prevent such unauthorized admission to the interior of the lock housing and observance of the movement of the tumblers to provide a pivoted plate or similar member which is normally spring biased to a position covering the combination changing key opening, but this variation has proved generally unsatisfactory because the guard plate for the, combination changing key opening which is usually pivoted to the lock housing cover plate adjacent one end of the guard plate can be readily punched out from covering relation with the combination changing key opening or shifted sufliciently to permit access of shim stock or other small instrumentalities through the combination changing key opening and into the interior of the lock housing.

An object of the present invention therefore is the provision of novel guard means for closing the rear cover plate opening of a combination lock housing through rates stem which the combination resetting key is inserted to prevent access to the resetting key opening or observation of the tumbler mechanism at all times except when the lock has been unlocked and expressly conditioned to permit changing of the combination.

Another object of the present invention is the provision of a novel guard means for the resetting key opening in combination padlocks for maintaining the opening covered against access except when the lock has been unlocked and expressly conditioned for combination resetting, which guard means is of simple construction of few parts which can be economically manufactured and which is so integrated with the rear cover plate of the padlock housing as to effectively resist forcing of the guard means from covering relation with the resetting key opening.

Another object of the present invention is the provision of novel guard means for the resetting key opening of combination padlocks wherein the location of the resetting key opening in the padlock cover plate is concealed by the guard means to further resist unauthorized access to the interior of the padlock housing.

Another object of the present invention is the provision of a novel guard mechanism for the resetting key opening in combination padlocks to prevent access to the resetting key opening except when the padlock has been unlocked and expressly set for combination resetting,

which mechanism requires no increase in the size of the padlock housing or in any way disturbs the relationship between the fence and tumbler mechanism or other parts of the lock assembly.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing showing only a preferred embodiment of the invention.

in the drawing:

Figure 1 is a rear elevation of an exposed shackle combination padlock embodying the present invention, parts of the padlock housing being broken away to illustrate the internal construction thereof.

Figure 2 is a vertical longitudinal section view of the 1 combination padlock, taken along the lines 2-2 of Figure 1. i Figure 3 is a horizontal transverse section view of the padlock taken along the lines 3-3 of Figure 1. t Figure 4 is an exploded perspective view of the two interconnected rotary elements forming the resetting opening guard means of the present invention.

Referring to the drawing wherein like reference characters designate corresponding parts throughout the several views, the structure embodying the preferred embodiment of the present invention comprises a combination padlock generally indicated at 10 having a lock housing 11 including a front wall 12, side walls 13, curved bottom wall 14 and top wall 15, all integrally formed with the front wall 12 to produce a rearwardly opening body. The top wall 15 is formed with a pair of laterally spaced circular openings in located adjacent the side walls 13 for receiving the legs of the usual U-shaped shackle 17 when the padlock is in locked condition. In accordance with conventional practice, one of the legs of the shackle 17 is slidably connected with the housing 11 so as to permit reciprocal movement of the shackle while the one leg always remains within the housing 11 while the end of the opposite leg of the shackle 17 when the shackle is shifted to its outermost position relative to the housing 11 clears the outer surface of the top wall permitting the shackle to be rotated about the axis of the leg which is retained 16 in the top wall 15, an integral shelf member 18 projects inwardly from one of the side walls 13 to underlie the shackle-receiving opening for the shackle leg which can be completely withdrawn from the housing 11, and integral arcuately curved walls 19 project inwardly from both side walls 13 along a circular path concentric with the axis of the rotary lock mechanism to be described, to a point near the medial longitudinal plane of the lock housing so as to provide a narrow opening between the inner ends of the walls 19 lying in the medial longitudinal plane of the housing. The walls 19 thereby provide a substantially complete protective enclosure about the cylindrical tumbler chamber 2% in the lock housing 11.

Thepadlock housing 11 is also provided with a removable rear. cover plate 21 which is attached to the side, bottom and top walls of the lock housing in any suitable manner.

Journalled in the front wall 12 of the padlock housing is an arbor 22 which has iixed on'the front end thereof the usual dial 23 which is disposed in accordance with conventional practice in overlying relation to the front wall 12 of the padlock housing, the dial 23 being rotatable to turn the arbor 22 and thereby control movement of the usual tumblers. The arbor 22 supports the usual driving cam 24 in fixed relation to the arbor at a point near the inner end of the arbor, the driving cam Z lbeing provided with the usual peripheral notch 25 for cooperation with the fence to be referred to hereinafter. The reference character 26 designates several tumblers which are constructed in the usual manner with outer annular disks 26 and inner annular hubs 26" rotatably supported on a tubular boss 27 integral with and projecting rearwardly from the front wall 12 of the padlock housing. The tubular boss 2'7 also serves as the hearing in which the arbor 22 rotates. The outer annular disk portions 26' of the tumblers 26 are provided with the ,usual'peripheral recesses for receiving the fence 28 for operation in the usual fashion of tumbler combination locks in which the dial is turned in opposite directions alternately for predetermined numbers of turns until thexperipheral recesses of'all the tumblers are in alignment .to release the fence and permit movement thereof to unlock the shackle. The -tumblers 26 are therefore provided with the usual lost motion connection and the drivingcam 24 has a conventional inwardly extending driving pin which engages a stop member on the rearmos't tumbler 26 to drive the rearmost tumbler on rotation of the dial 23 and through the lost motion interconnection between the rearrnost tumbler and the rest of the tumblers achieve rotation of all of the tumblers.

The tumblers 26 are mounted between the driving cam 24,,and the front wall 12 of the padlock housing with their circular edges adjacent to the curved bottom wall 14 of the housingsothat the, parts can be arranged compactlyv and occupy a minimum of space. The tumblers cooperate with the fence member 28 which is mounted above the tumblers and is reciprocally slidable in suitable guideways 29 in the direction of the longitudinal medial axis of the housing to bring the lower leg of the fence member-which extends laterally over the width of all of the tumblers 26 into contact with the tumblers. A plurality of coil springs 30 are disposed in the guideways 29 and bear upon projecting shoulders of the fence member 28 to urge the fence toward the top wall 15 out of contact with the tumblers 26. The fence member 28 is likewise provided with adownwardly projecting nose 31 opera-' tively associated with the driving cam 24% and carries a pivotally supported pair of locking arms 32 having outwardly directed locking portions positioned by the fixed pins 33 on the front housing wall 12 received in suitable notches in the locking arms to seat in the notches 17 of the shackle 17 and lock the shackle.

When the dial 23 has been rotated in accordance with a preselected combination to align theperipheral recesses of the tumblers 26 with the fence member 28 and the driving cam notch 25 is aligned with the downwardly projecting nose 31 on the fence 2%, outward manual pressure on the shackle 1'7 pivots the locking portions of the locking arms 32 inwardly toward each other about the fixed pins 33, and since the tumbler and driving cam recesses are aligned with the fence to receive the fence, the fence may be projected downwardly against the bias of the springs St) to seat in the aligned recesses and release the shackle 17 for sliding movement outwardly of the lock housing. If the tumbler recesses are not aligned with the fence member 23, the periphery of the nonaligned tumbler will intercept downward movement of the fence 28 and prevent sufficient movement of the fence to permit the locking arms 32 to pivot free of the shackle notches 17.

The parts thus far described are substantially conventional except for the protective shelf la; and walls 19 of the lock housing and correspond to the conventional padlock structure exclusive of the security interlock features described in my earlier Patent No. 2,673,457 granted March 30, 1954. This application has to do specifically with mechanism which prevents observance of the movement of the tumbler mechanism or gaining access to the tumbler chamber for resetting the tumbler combination except when the lock has been unlocked and reset to a special combination resetting position so that the combination cannot be reset by unauthorized persons or by someone who does not know the existing combination.

The construction of the tumblers 26 and the nranner in which the outer annular disks 26 of each tumbler are disconnected from the hub portion 26" to permit resetting of the combination forms no part of this invention, it being understood that the outer annular disks 26 are dis connected from the hubs 26 for resetting the combination by inserting a key through an opening 34 in the rear cover plate 21 and through corresponding openings in the outer annular disks 26' of the tumblers which are aligned with the key opening in the cover plate when the tumblers'are all moved to a predetermined combination resetting position. To prevent access to the resetting key opening 34 in the rear cover plate 21 and to prevent resettingthe combination by unauthorized persons, there is provided a movable guard mechanism indicated generally'by the reference character 35 having components located over the inner and outer faces of the rear cover plate 21 in the path of the resetting key which must be inserted through the key opening 3 5 to change the combination so as to completely block the key opening 34 and prevent'access to or observance of the tumblers through the-key opening. This guard mechanism comprises an outer'circular disk 36 and an inner circular disk 37 disposed over .the outer and inner faces, respectively, of the rear cover'plate 21in concentric relation with the axis of thearbor'22. Theinnermost end of the arbor 22 is provided withan integral portion 38 of reduced diameter which is received in a central aperture 39 in the innermost guard disk 37 and in a complementary aperture in the rear cover plate 21 journalling the inner end of the arbor. The outer and inner guard disks 36 and 37 are rigidly held together for rotation as a unit by a pair of rivets 40 interconnecting the two disks and extending through arcuate slots 41 in the rear cover plate 21. The outer guard disk 36 is provided with an annular peripheralflilange 42 projecting inwardly of the disk and the rear cover plate 21 is provided with an annular recess 43 to accommodate the outer guard disk 36 so that the outer surface thereof is flush with the outer face of the cover plate 21. The inner guard disk 3'7 is likewise provided with an'annular peripheral flange 5 which projects inwardly over the rear edge of the fence 28. This flange has a gate of slightly greater width than the fence 28 cut entirely-through the flange 44- and located along the flange to be aligned with the fence-receiving opening between the inner ends of the walls 19 to receive the rearmost edge portion of the fence when the guard mechanism is within its normal position preventing access to the resetting key opening 34. The flange 44 is also provided with a combination resetting gate 46 which is spaced from the gate 45 and may be selectively brought into alignment with the fence 28 and permit reciprocation of the fence when the combination is to be reset. The fence, as will be observed in Figure 2, is provided with a recess 47 in the rearmost portion of the fence which is forced in alignment with the flange 44 when the fence is seated in the aligned recesses of the tumblers and driving cam in unlocked condition. This recess 47 is of suflicient depth to receive the flange 44 and thereby permit rotation of the guard mechanism on the portion 38 of the arbor when the fence is in unlocked position.

The outer and inner guard disks 36 and 37 are provided with resetting key openings 43 and 49, respectively, which, as illustrated in Figure l, are spaced some distance from the key opening 34 in the rear cover plate when the gate 45 is positioned to receive the fence. The outermost guard disk 36 is also provided with rearwlardly projecting finger studs 50 which facilitate manual rotation of the guard mechanism. When the fence is in shackle locking position (Figure 2) the rear portion of the projection 31 of the fence 2% is seated in the gate 45 of the flange 44 so that any attempt at rotation of the guard mechanism would bring the side walls of the gate 45 into abutment with the fence 28 to prevent any appreciable rotation of the guard mechanism. The guard mechanism 35 is therefore held against rotation by the locked position of the fence and the key-receiving openings 48 and 49 are aligned with uninterrupted portions of the rear cover plate 21 in spaced relation to the cover plate key opening 34 so that no access can be had to the interior of the lock housing. In order to condition the lock housing to permit the resetting key to be inserted, the padlock must first be unlocked by adjustment of the tumblers in accordance with the proper combination and withdrawal of the shackle 17 to project the fence 28 into seated condition within the tumbler and driving cam recesses, in which position the fence notch 47 is in the path of rotation of the flange 44. The guard mechanism 35 can then be rotated within the limits permitted by the slots 41 in the cover plate 21 accommodating the rivets 40 to shift the resetting gate 46 of the flange 44- in fence-receiving position. This same rotation of the guard mechanism 35 shifts the resetting key openings 48 and 49 into alignment with the key opening 34 in the cover plate. The fence 28 must then be returned to locked position by manually forcing the shackle 1'7 inwardly of the padlock housing, so that the driving cam is freed from interlocked relation with the projection 31 of the fence 2%, and upon insertion of the resetting key through the openings 48, 34 and 49 and into the tumbler resetting key openings, to disengage the outer tumbler disks 26 from their hubs 2s", the dial 23 and driving cam 24 can then be rotated to establish the desired new combination. After the combination has been established, the resetting key is removed and the padlock must again be unlocked to bring the fence notch 47 into the path of the flange 49 to permit return of the guard mechanism to covering relation with the resetting key opening.

While but one particular embodiment of the invention has been particularly shown and described, it is apparent that various modifications may be made in the invention without departing from the spirit and scope thereof, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art and are set forth in the appended claims.

I claim:

1. In a combination padlock, the combination with a padlock housing including a wall having a combination resetting key opening therein, rotatable tumblers, a driving cam therefor, a rectilinearly reciprocable fence operatively associated with said tumblers and driving cam, and

means holding said driving cam against rotation when said fence is out of locking position, of a guard mechanism comprising a pair of relatively fixed circular disks disposed over the inner and outer surfaces of said Wall in covering relation with said wall opening for normally blocking said wall opening, said disks having inwardly projecting annular peripheral flanges and aligned resetting key open ings therein disposed out of registry with said Wall open ing when said disks are in a guard position, means pivot ally supporting said disks on said wall for rotation about their axes from said guard position to a combination re-" setting position, the peripheral flange on the innermost of said disks having gates therein receiving said fence to permit reciprocation thereof between locking and unlocking positions only when said disks are in said guard position and said resetting position, means bounding said gates for engaging said fence to prevent rotation of said disks when said fence is in locking position, and said fence having a recess therein disposed to receive the flange of said innermost disk and permit rotation of said disks only when said fence is in unlocking position.

2. In a combination lock, the combination with a lock housing including a wall having a combination resetting key opening therein, rotatable tumblers, a driving cam therefor, and a fence operatively associated with said tumblers and driving cam, of a guard mechanism comprising a pair of cover plates held together against relative movement and rotatably mounted on said wall, said plates being disposed over the inner and outer surfaces of said wall in covering relation with the wall opening for normally blocking both the entrance and exit of said wall opening, said plates having aligned resetting key openings therein normally spaced out of alignment with said wall opening, means projecting from one of said plates for engaging said fence upon attempted rotation of said cover plates from said blocking position when said fence is in locking position to prevent rotation of said plates, said fence having a relieved portion for receiving said projecting means when said fence is in unlocking position to permit rotation of said plates to align the openings therein with said wall opening, and said pair of cover plates having means releasing said fence for return to locking position when said cover plates are positioned with their openings in alignment with said wall opening.

3. In a combination lock, the combination with a lock housing including a wall having a combination resetting key opening therein, rotatable tumblers, a driving cam therefor, and a fence operatively associated with said tumblers and driving cam, of a guard mechanism comprising a pair of relatively fixed circular disks disposed over the inner and outer surfaces of said wall in covering relation with said wall opening for normally blocking said wall opening, said disks each having inwardly projecting annular peripheral flanges and aligned resetting key openings therein disposed out of registry with said Wall opening when said disks are in a guard position, the outer surface of said wall having an annular recess therein complementary to said annular peripheral flanges to receive the flange of the outermost one of said disks seated therein, means pivotally supporting said disks on said Wall for rotation about their axes from said guard position to a combination resetting position wherein the openings in said disks are aligned with, said wall opening, the flange of said innermost disk having spaced radial guideways for receiving said fence to permit movement of said fence relative tosaid disks between locking and unlocking positions when said disks are in said guard position and said resetting position, means interlocking said flange of said innermost disk with said fence to restrain the latter against movement relative to said disks at all positions of said disks between said guard position and said resetting position when said fence is in unlocking position, said flange of said innermost disk having means bounding said guideways to engage said fence for preventing rotation 4 of-saiddi'sks, when said fence is in locking position, and said fence having means permitting rotationof said disks about their axes when said fence isin unlocking position.

4. In a combination padlock, the combination with a padlock housing including a wall having a combination resetting key opening therein, rotatable tumblers, a driving cam therefor, a rectilinear-1y reciprocable fence operatively associated with said tumblers and driving cam, and means holding said driving cam against rotation when said fence is out of locking position, of a guard mechanism comprising a pair of aligned parallel relatively fixed circular disks disposed over the inner and outer surfaces of said wall in covering relation with said Wall opening for normally blocking said wall opening, said, diskshaving aligned resetting key openings therein disposed "out of registry with said wall opening when said disks are in a guard position, means pivotally supporting said disks on said wall for rotation about their axesfrom :said guard position to a combination resetting position; the axes of said disks being disposed in the plane of movement of said fence perpendicular to the direction ofjmovement thereof, the innermost disk having peripheral radial guideways therein for receiving said fence to permit reciprocation thereof between locking and unlocking positions only when said disks are in said guard position and said resetting position, said innermost disk having means on the periphery thereof adapted to interlock with said fence at all positions of said disks between said guard position and said resetting position When said fence is in unlocking position to hold said fence against movement fromsaid unlocking position, means bounding said guideways for engaging said fence to prevent rotation of said disks when said fence is in locking position, and said fence having means to permit rotation of said disks when said fence is in unlocking position.

5. In a combination shackle padlock, a lock housing including a wall having a combination resetting opening therein, rotatable tumblers, a driving cam therefor, and a fence operatively associated with said tumblers and driving cam for rectilinear reciprocal movement along a radial axis of said tumblers and having an elongatedv rearwardly projecting rib extending along said radial axis; said fence locking said driving cam against rotation when;-

said fence is in unlocking position, a guard mechanism rotatably mountedon' said wall having coveringmeans blocking both the entrance and exit of said wall opening;

when said mechanism is in guard position, said guard mechanism having aligned resetting key openings therein disposed out'of alignment with said wall opening, means for rotatin said guard mechanism to a combination on disposing said openings therein in registry with said wall opening, inwardly projecting means on said guard mechanism preventing reciprocation of said fence between shackle locking and unlocking positions at all positions of said guard mechanismexcept said guard and resetting positions and having guideways'interfitting with said rib of said fence for permitting reciprocation of said fence between said shackle locking and unlocking positions when said guard mechanism is in said guard and resetting positions, said inwardly projectingmeans having shoulders disposed adjacent the lateral surfaces of said rib when said rib is interfitted with said guideways for barring rotation of said guard mechanism when said fence is in shackle locking position, and said fence rib having a rearwardly opening recess disposed to receive said inwardly projecting means when said fence- References Cited in the file of this patent UNITED STATES PATENTS Eifiert et al. Oct. 30, 1951 Miller Mar. 30, 1954 

